Start by determining how much fabric you are going to need. Fabric widths will vary based on type of fabric, this particular fabric was a crafting and quilting fabric so the width was approximately 43" wide.
For this room, the ceilings are 9ft tall, so based on the wall width, I needed 10 yards. I found the fabric for $6.99/ yard with 40% off, so the project total came in at less than $50. You will want to trim off the selvage edge of the fabric and allow about 1/2" edge for any shrinkage.